1. Field
The present disclosure relates generally to manufacturing and servicing vehicles, especially aircraft. More particularly, the present disclosure relates to a method of repairing or reworking inconsistencies in components of the aircraft that allow the performance of the repair to be monitored using optical inspection techniques.
2. Background
Monitoring the health, state, and/or quality of on-aircraft bonded structural repairs, such as doubler repairs on composites or metals, can be expensive and challenging using traditional NDE (non-destructive evaluation) equipment. The use of a trained NDE technician to inspect a repair for signs of early degradation can be time consuming and may require the aircraft to be taken out of service while the inspection is performed. Also, bond testers and ultrasonic test equipment typically used to perform the inspection maybe too costly for smaller airlines. Current techniques for structural health monitoring of repairs require equipment that flies with the airplane or connects into circuitry attached to sensors that are pulsed to check the repair with ultrasonic structural waves. These systems are costly and can add undesired weight to the aircraft.
Accordingly, there is a need for a simple and rapid method of detecting initial signs of degradation of a repair, such as a loss of adhesion or a change in its strain pattern. There is also a need for a repair that incorporates a tell-tale feature allowing optical observation of degradation or other changes during routine, periodic service checks.